最近在做游戲服務(wù)分層的時候，一直想把mysql的訪問獨立成一個單獨的服務(wù)DBGate，原因如下:
- 請求收攏到DBGate，可以使DBGate變?yōu)闊o狀態(tài)的，方便橫向擴展
- 當請求量或者存儲量變大時，mysql需要做分庫分表，DBGate可以內(nèi)部直接處理，外界無感知
- 通過restful限制對數(shù)據(jù)請求的形式，僅支持簡單的get/post/patch/put 進行增刪改查，并不支持復雜查詢。這個也是和游戲業(yè)務(wù)的特性有關(guān)，如果網(wǎng)站等需要復雜查詢的業(yè)務(wù)，對此并不適合
- DBGate使用多進程模式，方便控制與mysql之間的鏈接數(shù)，進行mysql訪問量閥值保護
- 方便在DBGate上進行訪問量統(tǒng)計，慢查詢統(tǒng)計、權(quán)限控制等等一系列邏輯
- 目前是使用python，以后要使用其他語言進行mysql操作時，只要進行標準的http請求即可，不會出現(xiàn)不兼容的情況
當然壞處也是有的：
- 首當其沖就是單次請求的響應(yīng)時間變長，畢竟中間加了一層服務(wù)，并且還是http格式
- 部署上比原來復雜了一些，很多對mysql直接操作的思維需要進行轉(zhuǎn)變，一開始可能會有些不適
不過總的來說，還是利大于弊，所以最終還是決定搭建DBGate
當然，我們不可能去手工挨個寫每個庫表對應(yīng)的restful服務(wù)，值得慶幸的是django和flask都提供了對應(yīng)的解決方案，我們一個個介紹.
Flask
參考鏈接: flask-restless
flask-restless使用方法比較簡單，我直接貼一下代碼即可:
# -*- coding: utf-8 -*-
import datetime
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_restless import APIManager
app = Flask(__name__)
db = SQLAlchemy(app)
restless = APIManager(app, flask_sqlalchemy_db=db)
class User(db.Model):
"""
user
"""
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(255), unique=True, nullable=False)
password = db.Column(db.String(255), nullable=False)
create_time = db.Column(db.DateTime, nullable=False, default=datetime.datetime.utcnow)
login_time = db.Column(db.DateTime)
restless.create_api(User, methods=['GET', 'POST', 'DELETE', 'PATCH', 'PUT'], results_per_page=100)
db.create_all()
if __name__ == '__main__':
app.run(port=25000)
# -*- coding: utf-8 -*-
import datetime
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_restless import APIManager
app = Flask(__name__)
db = SQLAlchemy(app)
restless = APIManager(app, flask_sqlalchemy_db=db)
class User(db.Model):
"""
user
"""
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(255), unique=True, nullable=False)
password = db.Column(db.String(255), nullable=False)
create_time = db.Column(db.DateTime, nullable=False, default=datetime.datetime.utcnow)
login_time = db.Column(db.DateTime)
restless.create_api(User, methods=['GET', 'POST', 'DELETE', 'PATCH', 'PUT'], results_per_page=100)
db.create_all()
if __name__ == '__main__':
app.run(port=25000)
其對應(yīng)的restful操作如下:
獲取用戶列表: GET /user
添加用戶: POST /user
獲取單個用戶: GET /user/1
覆蓋單個用戶: PUT /user/1
修改單個用戶: PATCH /user/1
獲取用戶列表: GET /user
添加用戶: POST /user
獲取單個用戶: GET /user/1
覆蓋單個用戶: PUT /user/1
修改單個用戶: PATCH /user/1
注意:
- 在http請求中，記得加入header: Content-Type: application/json
- flask-restless中，PUT和PATCH一樣，都是傳入什么字段，只修改什么字段，不會完全覆蓋
Django
參考鏈接: Django REST framework
Django用起來要更復雜一些，也因為django版自帶了一個可視化的操作頁面，如下:
1. 在settings中添加:
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REST_FRAMEWORK = { # Use hyperlinked styles by default. # Only used if the `serializer_class` attribute is not set on a view. 'DEFAULT_MODEL_SERIALIZER_CLASS': 'rest_framework.serializers.HyperlinkedModelSerializer', # Use Django's standard `django.contrib.auth` permissions, # or allow read-only access for unauthenticated users. 'DEFAULT_PERMISSION_CLASSES': [ #'rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly', 'rest_framework.permissions.IsAdminUser', ]} REST_FRAMEWORK = { # Use hyperlinked styles by default. # Only used if the `serializer_class` attribute is not set on a view. 'DEFAULT_MODEL_SERIALIZER_CLASS': 'rest_framework.serializers.HyperlinkedModelSerializer', # Use Django's standard `django.contrib.auth` permissions, # or allow read-only access for unauthenticated users. 'DEFAULT_PERMISSION_CLASSES': [ #'rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly', 'rest_framework.permissions.IsAdminUser', ]} |
2. 通過startapp建立一個app: demo
3. 修改demo的models:
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class User(models.Model): # key是保留字 password = models.IntegerField() nick = models.CharField(max_length=255) create_time = models.DateTimeField(default=datetime.datetime.now) class User(models.Model): # key是保留字 password = models.IntegerField() nick = models.CharField(max_length=255) create_time = models.DateTimeField(default=datetime.datetime.now) |
4. 在demo下新建serializers.py
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<p>from rest_framework import serializers<br>from models import User</p>class UserSerializer(serializers.ModelSerializer): class Meta: model = User from rest_framework import serializersfrom models import User class UserSerializer(serializers.ModelSerializer): class Meta: model = User |
5. 在demo下修改views.py
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from django.shortcuts import renderfrom rest_framework import viewsetsfrom serializers import UserSerializerfrom models import Userclass UserViewSet(viewsets.ModelViewSet): queryset = User.objects.all() serializer_class = UserSerializer from django.shortcuts import renderfrom rest_framework import viewsets from serializers import UserSerializerfrom models import User class UserViewSet(viewsets.ModelViewSet): queryset = User.objects.all() serializer_class = UserSerializer |
6. 在demo下新建urls.py
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import os.pathfrom django.conf.urls import patterns, include, urlfrom django.conf.urls.static import staticfrom django.conf import settingsimport viewsfrom rest_framework import routersappname = os.path.basename(os.path.dirname(os.path.abspath(__file__)))router = routers.DefaultRouter()router.register('users', views.UserViewSet, appname)urlpatterns = patterns('', url(r'^', include(router.urls)),) import os.pathfrom django.conf.urls import patterns, include, urlfrom django.conf.urls.static import staticfrom django.conf import settingsimport views from rest_framework import routers appname = os.path.basename(os.path.dirname(os.path.abspath(__file__))) router = routers.DefaultRouter()router.register('users', views.UserViewSet, appname) urlpatterns = patterns('', url(r'^', include(router.urls)),) |
7. 在mysite.urls下include demo.urls和rest_framework.urls
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urlpatterns = patterns('', url(r'^demo/', include('demo.urls')), url(r'^admin/', include(admin.site.urls)), url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))) urlpatterns = patterns('', url(r'^demo/', include('demo.urls')), url(r'^admin/', include(admin.site.urls)), url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))) |
8. 執(zhí)行初始化數(shù)據(jù)操作:
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python manage.py syncdb python manage.py syncdb |
之后訪問: http://127.0.0.1:8000/demo 即可看到如下界面了:
對應(yīng)的測試代碼如下:
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import jsonimport requestsfrom urlparse import urljoinBASE_URL = 'http://127.0.0.1:16500/'AUTH = ('admin', 'admin')def test_get_user_list(): rsp = requests.get(urljoin(BASE_URL, '/demo/users/'), auth=AUTH, headers={ 'Accept': 'application/json' }) assert rsp.okdef test_post_user_list(): json_data = dict( password=0, nick='oo', create_time='2014-03-3T03:3:3' ) rsp = requests.post(urljoin(BASE_URL, '/demo/users/'), auth=AUTH, headers={ 'Accept': 'application/json', 'Content-Type': 'application/json', }, data=json.dumps(json_data)) assert rsp.okdef test_get_user(): rsp = requests.get(urljoin(BASE_URL, '/demo/users/1'), auth=AUTH, headers={ 'Accept': 'application/json', 'Content-Type': 'application/json', }) assert rsp.okdef test_put_user(): json_data = dict( password=100, nick='xx', create_time='2014-03-3T03:3:3' ) # 注意最后的 / rsp = requests.put(urljoin(BASE_URL, '/demo/users/1/'), auth=AUTH, headers={ 'Accept': 'application/json', 'Content-Type': 'application/json', }, data=json.dumps(json_data), ) assert rsp.ok, rsp.status_code |
Django REST framework 是嚴格區(qū)分PUT和PATCH的，這一點和flask-restless 不一樣，需要注意。
OK，就這樣。
